INHIBITION OF COLLAGENASES FROM MOUSE LUNG-CARCINOMA CELLS BY GREEN TEA CATECHINS AND BLACK TEA THEAFLAVINS

Theaflavin and theaflavin digallate, which are components of black tea were examined by in vitro invasion assay with mouse Lewis lung carcin oma LL2-Lu3 cells, which are highly metastatic. The compounds inhibite d invasion by the tumor cells. Gelatin zymography showed that the cell s secreted matrix metalloproteinases (MMPs), probably including MMP-2 and MMP-9, which may be involved in tumor cell invasion and metastasis . Theaflavin and theaflavin digallate also inhibited MMPs from the cul ture medium of these tumor cells, as did (-)-epigallocatechin gallate. These results suggest that theaflavin, theaflavin digallate, and (-)- epigallocatechin gallate inhibit tumor cell invasion by inhibiting typ e IV collagenases of the LL2-Lu3 cells.